考虑非线性剪切及界面滑移拉伸效应的连梁纤维模型研究  

Research on fiber model of coupling beams considering nonlinear shear and interfacial slip tensile effects

作　　者：虞终军 王建峰 段炼 YU Zhongjun;WANG Jianfeng;DUAN Lian(Architectural Design and Research Institute of Tongji University(Group)Co.,Ltd,Shanghai 200092,China)

机构地区：[1]同济大学建筑设计研究院(集团)有限公司,上海200092

出　　处：《建筑结构学报》2023年第12期233-240,共8页Journal of Building Structures

摘　　要：为得到适用于工程应用的连梁模拟方法,通过对现有连梁数值模拟方式以及钢筋混凝土构件考虑剪切非线性的方式进行梳理,指出目前可行的方式是采用分布塑性铰单元在截面层次上指定非线性恢复力模型进行模拟。基于OpenSees分析平台给出了小跨高比钢筋混凝土连梁模型化方法。该连梁模型由带非线性剪切本构的纤维单元和两端零长度非线性剪切-滑移拉伸弹簧组成。结合文献给出了非线性剪切本构开裂点、峰值点和卸载段刚度,以及非线性剪切-滑移弹簧刚度的计算公式。并对4个不同材料强度、不同尺寸和配筋的连梁试件进行数值模拟。结果显示,在初始剪切刚度、受剪承载力、刚度退化、滞回耗能和捏缩效应等方面与试验曲线均吻合较好,表明建议的连梁模型化方法对小跨高比钢筋混凝土连梁滞回特性具有较好的预测精度。连梁的滞回性能受到剪切及界面滑移拉伸变形作用的显著影响,非线性剪切变形及界面滑移拉伸变形在小跨高比钢筋混凝土连梁模拟中不可忽略。In order to obtain a coupling beam simulation method suitable for engineering,this study reviews the existing numerical simulation methods for coupling beams and the treatment of shear nonlinearity in reinforced concrete members.It’s concluded that the currently feasible way is to use distributed plastic hinge elements in the section to hierarchically specify a nonlinear restoring force model for simulation.Based on the OpenSees analysis platform,a modeling method for reinforced concrete coupling beams with small span-to-height ratio is suggested.The coupling beam model consists of fiber elements with nonlinear shear constitutive and zero-length nonlinear shear-slip tension springs at both ends.Combined with the literature,the calculation formulas of nonlinear shear constitutive cracking point,peak point,unloading section stiffness and nonlinear shear-slip spring stiffness are given.Numerical simulations are carried out on four coupling beam specimens with different material strengths,different sizes and reinforcements.The results show that the initial shear stiffness,shear bearing capacity,stiffness degradation,hysteretic energy dissipation and pinch effect are in good agreement with the experimental curves,indicating that the proposed modeling method has good prediction accuracy for the hysteretic characteristics of coupling beams with small span-to-height ratio.The hysteretic performance of coupling beams is significantly affected by shear and interface slip tensile deformation.Non-linear shear deformation and interface slip tensile deformation cannot be ignored in the simulation of reinforced concrete coupling beams with small span-to-height ratio.

关 键 词：钢筋混凝土连梁 剪切非线性 OPENSEES 界面滑移拉伸 纤维单元 

分 类 号：TU375[建筑科学—结构工程] TU311.41